| 摘要 |
<p>The biological filter (1) consists of a reactor (2) with inlets (3, 6) at the bottom for the effluent to be filteres and an oxygenated gas, an outlet (14) at the top for the filtered effluent, and filters (18) between with supporting layers for a biomass having a density below that of the effluent to be filtered. The supporting layers are of expanded plastic or mineral balls of 1 - 30 mm diameter and having a density of 0.5 - 1. The reactor is subdivided by grilles (19a, 19b, 19c) that retain the filtering medium for at least two filtering stages (20a, 20b, 20c) and an upper outlet stage (17). Each of the filtering stages has its own filtering layer and an outlet the bottom for drawing off any surplus biomass, determined by a detector (26) with a wave bundle emitter and receiver.</p> |
